The medial septum and diagonal bands (medial septal region) is a division of the basal forebrain that is[unreadable] affected by aging and in particular by Alzheimer's disease. The medial septal region contains a[unreadable] heterogeneous population of neurons, including cholinergic and non-cholinergic projection neurons and[unreadable] interneurons. Even though inputs from septal neuronal populations are necessary for the normal processing[unreadable] of information by hippocampal and neocortical networks, only fragmented information on the anatomy,[unreadable] electrophysiology and pharmacology of most septal neuronal populations (cholinergic cells are the[unreadable] exception) is currently available. In addition, the connectivity of septal neuronal populations and their[unreadable] alteration with aging is fundamentally unknown. This proposal is dedicated to identify synaptic connections[unreadable] among septal neurons, the functional circuits established through these connections and the aging effect on[unreadable] septal synaptic connectivity. The proposed experiments will facilitate the modeling of normal and age-altered[unreadable] septal connectivity. They also may result in therapeutic strategies dedicated to modulate cognitive processes[unreadable] and alleviate the burden of age-related disorders, in particular Alzheimer's disease. The experimental[unreadable] strategy delineated in this proposal will also provide strong opportunities for intra- and inter-institutional[unreadable] collaborations and new career development opportunities for UTB/TSC faculty.